So, newcomer to the forum but old hand at exercise 1 here. Given that I just signed up, I'm not sure whether or not I should mark this as complete or whether it needs more revision. Instead, these are just some things I would recommend you keep an eye on.

First up, your line control is good. There's a bit of wobble there, but nothing you can't fix via repetitive practice. The lines for the planes and boxes have the most notable wobble, so I'd recommend that you put a bit more focus on the ghosting planes exercise, this time with the goal of smoothly going from end to end instead of trying to reach the points. The points will come after you've built up a good flow. A good point to aim for is when it almost feels like there's an invisible ruler that you're using. But other than that, your lines are good enough that I can say that the first two exercises are complete (that is, ghosting lines and superimposing lines). That doesn't mean that you can't get anything more out of them, oh no. Instead, your lines are good enough that you can drop those two exercises into your warm-ups instead of homework.

Your ellipses come next. Here, there's the matter of deformation. This is likely because you've not yet managed to properly get the muscles down. This sort of deformation—where one side is flat and the other is more rounded—usually means that you sped through the movement too fast. Slow down a bit. If you notice, the ellipse in planes exercise is much cleaner. Try to use the same speed for your normal ellipses as well.

Finally, boxes. Your boxes suffer from a combination of improper line control and weight. Your perspective looks fine to start with, but there are some subtle things that are off. For example, in your organic boxes, some of them are warped so that it looks like the insides of the box (look at page 2, panel 2, bottom left box for an example of this—the boxes left side plane widens instead of narrowing, which makes it look like the inner side rather than the outer side). Furthermore, your boxes all have the exact same line weight, which makes it difficult to differentiate between the inner and outer sides. I'd recommend using one line to construct the box, then going back and superimposing a second line on the silhouette and front plane of the box. This makes the box's outside darker an easier to differentiate.

Now that the criticisms are done, time for the praise. To start with, I applaud your determination. You've managed to stick with the exercises from start to end. Right now, it might not seem like much. I know how sometimes it can be disheartening to put down so much work only for some jackass to show up and start telling you that there were mistakes in there. But that's just it—those are only mistakes. They are mis takes. They aren't a sign that you've done wrong or you've done bad—no. These are a sign that the level you strive for is still within your reach—only now it's so much closer. I won't promise that dull work is going to be exciting, but I will tell you that even those exercises that you right now hate will see you improve. But that doesn't mean that you should throw yourself at them. Don't bullrush them, that won't see you improve. If your think you're rushing through, then spread out the exercises over multiple days instead of rushing through an exercise a day. You'll be less liable to burn out that way.

Take a short break. Spend a day drawing something—anything really. Then, once you've drawn it, put it to the side. Once you've done an exercise, whether perfectly or not, whether you have to redo it or not, spend a day on drawing something. Once you've gone through Drawabox, you'll have a record of how you've improved. You'll be able to see your improvement laid out before you.